Field of the Invention
The present invention relates to an image processing device and system, an image processing method, and a medium. More specifically, the present invention relates to an image processing device and system, an image processing method, and a medium for performing noise reduction on an image.
Description of the Related Art
In recent years, the definition of a display device becomes higher, and higher image quality is desired. In order to achieve higher image quality, it is important to reduce noise in an image.
Japanese Patent Laid-Open No. 2007-536662 proposes a noise reduction method called a nonlocal means (NL-means) filter and using the self-similarity of subject space. The NL-means filter is a method in which noise is reduced by replacing the signal value of a target pixel with the weighted average signal value of a plurality of pixels around the target pixel. On this occasion, weights used for the weighted average are determined according to distances between a vector which includes, as a component, each signal value of a partial region with the target pixel at a center and vectors which are generated from pixels around the target pixel in a similar manner.